Depth-regulator for submarine mines in tidal waters



June 8, 1937. v I D. RUDMANN 2,082,849

DEPTH REGULATOR FOR SUBMARINE MINES IN TIDAL WATERS Filed Jan. 19, 1935l4 l5 l6 l7 /8 I 28 55 Y 29 54 N I 5/ s h I 49 I f\ 8 I Y 48 0 00 3/ 47ooo 4 v $95 32 46 33 ii #677 Z W i DeM LZZQ, poccliw'wm the water. I

Patented June 85 1937 PATENT OFFICE DEPTH-REGULATOR FOR SUBMARINE Y,MINES IN TIDAL WATERS Demeter Rudmann, Flume, Italy Application January19, 1935, Serial No. 2,509

.In Italy October 13,1934

1- Claim. (01. 10 2-4) My invention relates to a depth regulator forsubmarine mines particularly intended for use in tidal waters and Wherethere are currents of variable strength. It isa known fact that in suchwaters the mines are commonly either toolow or too high, accordingto theVariations in the depth of the water and the strength of current. Theobject ofmy new depth-regulator is to keep mines at a correct constantdepth below the level of In the present apparatus embodying my inventionthe raising and lowering of the mine are efiected bya mooring ropewoundupon a drum which is indirectly energized. by the current and controlledby theexternal hydrostatic pressure.

The: new depth-regul'atoris distinguished from all others essentially bythefact'that it is an entirely separatesupplementary mechanism which isapplicable to every kindvof submarine mine without the necessity ofeither the shell or the anchor-gear of the mines being modified. V

Moreover the new depth-regulator is provided with safety-gears andaccessories capable of insuring perfect working, and all difficultiesliable to arise from'incrustation of shells, seaweed and the like, areavoided because all delicate mechanisms (suchas wheel-gears, engagingclutch, pressure, diaphragms etc.) are enclosed in 2. casing filled withlubrificating substance.

The depth-regulator embodying my invention is illustrated in theaccompanying drawing, in

which Fig. I shows its application to a mine of spherical shape. I

Figs.-II and III show two moored mines provided with depth-regulator,the first immediately after-the laying, the second in definitiveposition. l r vFig. IV. shows a central section through thedepth-regulator in'which are visible essentially three parts.

1)v The head-The head 2| comprises an inner casing I4, including theengaging clutch 4152 and 41-48 respectively for forward and reversetransmission; two reducing worm-wheel-gearings 49--50 and. 48-46 theprincipal toothed wheel 45 which meshes with. the fixed gearing 44 ofthe outer casing; the inverting gearings 5 4--l'l-53'5l,for rearwardtransmission; and finally the stop-gear 55-45, lBll.

,(2) The rope-drum-Ihis rope-drum 22 is attached to the inner casing I4of the head. Beneath the rope-drum there are provided three rope leadingrollers 4lI-4l-42 (the last roller is movable also in axial direction inorder to insure a regular winding-up of the rope) and the safetygearagainst mooring shock 38-3l36-3543.

(3) The turbine.The turbine is equipped with outwardly projecting blades33. The turbine turns upon a centralpivot attached to the ropedrum andincludes two .pressure-sensitive-diaphragms 2426; the immersion-spring28; and the friction-clutch 29 which connects diaphragm 26 with theengaging axle 34. I

Figure 'I shows, how the depth-regulator is to be fastened to. aspherical mine, which is the most commonly used. I

At the place for attaching the usual mooring rope is shackled the upperend of a little'chain B of about one meter in length, which chain thenpasses over a support-bolt I (which may be screwed eventually 'on theplace of a lead-horn). The other end of the chain is fastened by meansof a swivel 2 and a shock-absorber 3 to the head 2| of the regulator.

Thus the regulator rests with its head against a rubber .(or cork)bolster 4 at the right side of the mine-shell. The chain 6' which keepssuspended the apparatus and the mooring rope I which holds it to theanchor must be well stretched in order'to avoid damages to the mechanismby the latter-bumping against the mine during mooring act. After a shortstay in water the loosening gear 8 of themine lets the anchor go, themine turns to'the right side due to the absence of balance and. thetension of rope. The chain 6 drops consequently from its support-bolt l,and thus the situation shown in Figure II arises.

The depth-regulator is applicable to every kind of moored-mines howeverthey may be shaped (spherical, cylindrical, oval or otherwise) andhowever its mooring gear may be shaped (plum met gear, hydrostatic gearetc).

. Because of the necessity of resisting the lowering effect of strongcurrents theactual mines with fixed mooring length are provided with agreat deal of residual buoyancy. Itis therefore sure that all sorts ofsubmarine mines are able to bear the weight of the depth-regulatorwithout any difficulty. The partial loss of buoyancy due to the weightof the regulator does not reduce the efliciency of the mines, as theregulator compensates entirely the lowering effect of current by acorresponding lengthening of the mooring rope. Only in case the mine isprovided with an automatic contact breaker controlled by'tension of themooring rope (safety gear for mines with broken moorings), it will benecessary to replace the saiety-gear-spring by anew one of greater whichremains however a little slack, as shown in Figure II, at In. Thus thefirst shock of mooring is transmitted not to the internal mechanismsbutto the depth-regulator casing-and to the shook-absorber 9 inserted inthe chain respective? ly (Figure II).

After being some time in the water when the rope-drum 22 has made aboutT 6 of a revolution;

the nose 43 of the spring-bolt 35 is released. .The bolt moves to theleft, and the link 36 drops. The mooring rope is now hanging directly onthe regulator-rope 39 (position shown in Figure III). The second shock,due to the dropping of'link 36, is obviously very slight, since thestretching :by

i a few'centimeters of the slack 10 in rope39,

(Fig. II) permits only a slight acceleration of the As-shown by Fig.III, the depth-regulator, when the mine is definitely anchored, hangs adistance of about one meter beneath .the mine and-the blades 33 of itsturbine are exposed to the effect of the current. In the drawing onlytwo vanes are shown '33 but in reality thereare 20-24 of such blades.

Due to the efiect of the swivel at H- and I3 and to the circumstancethat the centre of the hydrodynamic pressure isfsituated behind thesuspension-point [9 or 20, the-depth-regulator always swings away fromthe current and thus keeps its longitudinal axis exactly current. a 1

Under the effect of the currentthe turbine keeps upa slow continuousrotation (about 1'7 revolutions a minute in a current of two miles anhour) which is always in the same sense with regard to the mooring-rope.The power deployment of the mechanism depends on the dimension of theturbine, on the ratio ofreduction of the gear wheels and obviously alsoon the speed of current. Experiments have demonstratedthey may easily bechecked by calculationthat acceptable dimensions of' the turbineguarantees the necessary power for a reliable performance of thedepth-regulator, even in currents of feeble strength (one mile an hour).When however the current'rises-above a speed of two miles an hour, therewill then arise an excess of power. v

- cated by diaphragm 26-and friction clutch 29 to the engaging axle34.When the mine is deeper than predetermined'by the tension of theimmersion-spring 28, an external pressure of the water,

penetratingthrough the apertures '23, is exerted in the direction of thev 49-504846-45-44 to work. The whole inner casing I4 and rope-drum 22rotate in an opposite direction to the turbine, and the rope 39 is beingunwound with result that the mine rises. The movement is quite slow dueto the high reduction ratio of the two worm-wheel-gearings working inseries. The drum um-olls about three meters of rope during an hour in acurrent of two miles.

When the mine, due to the unrolling of the .rope, has risen to a heightin which there exists abalance between the external pressure and theforce of. the immersion-spring 28, the engaging axle 34is moved back tothe left and the clutchmembers 41-18 become disengaged with the result'that the mine ceases its rising movement,

as it .hasarrived at the predetermined right depth. In this position theslow rotation of the turbine continues without moving the internalwheelgearihgs. It should be mentioned that the rope cannotunroll underthe effect of its own tension under' any circumstance; theworm-wheel-gearings act as an automatic stop;

If the mine-by the unrolling of the rope should exceed the proper depthand rise too high, the tension of the spring 28 (due to the weakening ofthe external pressure) would displace the engaging axle yet more towardthe left with the result that the clutch-members 41 and 52 becomeengaged. Thus, would come into actionthe-forward transmission5249-5048'-464544 and the gearings 5I-53I'|54 would-run without load.The inner casing 14 and the rope-drum 22 -would rotate this time in thesame sense as the. turbine. The rope would therefore wind upon the druminstead of unrolling-therefrom,

as it did in the first case, and the mine would descend. 1

As experiments have shown, the sensibility of the hydrostatic gear fordepth-differences can be increased to a ratio which responds also-to 20centimeters of level-difference, which is more than accurate enough forpractical purposes. And it need not be-"feared that due to thecontinuous working, the pinions will be subjected to any great wear andtear. Thepinions have a foroe of about 3/1000 of the rope-tensionexerted on them. Therefore, it is alwayspossible to give them dimensionswhich secure a minimum specific pressure, eventually also by an increasein the number of pinions upto 8 or 12.

In order to prevent excess rotation of the ropedrum beyond the limit ofabout ten'meters of rope (that is practically the necessary length) theapparatus is provided with a stop-gear acting on the wheel I1. a

It should'be noted that in Figure IV, for the sake of clearness, thereis omitted a vertical axle which connects movement of worm 48 (by meansof a Worm-wheel) with the -worm-gear 55. Due to the Very slow movementproduced by three worrh-wheel-gearings, working in series (dB-50, 4855,55|5)- the stop-nose 16 accomplishes only of a revolution during theentire unrolling of ten meters of rope. The wheel I6 twice stops themovement of the nose H, the first time when the rope is completely woundup, and the second time when the rope is completely wound off. Returningof nose !6 is obviously possible only in the case that after astoppingthere sets in a movement in the opposite sense to that stopped;the latter is absolutely prevented. 1

1 In order to prevent overworking of'the sensitive-diaphragms and of theinternal wheel-gears, the depth regulator is provided with a safetygearwhich comprises a'fri ction-clut'ch 29 insert- V engaging axle 34.

In order to prevent deformation of the pressure sensitive diaphragms 24and 26 due to overworking through exceptionally strong externalpressures (for example in the case of irregular mooring) there areprovided two fixed walls 25 resp. 21, which limit the possible movementsof the diaphragms in a way which does not interfere with theirelasticity.

The depth-regulator has an advantage which ought to be once moreemphasized, to wit, all its somewhat delicate mechanisms are completelyenclosed in a casing filled with lubricating substance, thus being wellprotected against incrustations of shells and the like. Well dimensionedstufiing boxes (omitted from the drawing for sake of clearness) avoid,or at least retard, loss of the lubricating oil. Also when after being along time in water, instead of pure oil an emulsion arises, that hasslight damaging influence on the functioning of the regulator, as a gooddose of arsenic or other poison added to the oil prevents the growth ofincrustations in the interior of the regulator.

And finally when perhaps, after having for many years been in water, thedepth-regulator will efiectively cease to function, and the minesprovided with the depth-regulator will thus become exactly like a minewithout it (probably due to incrustations of the rope by shells notsufiiciently eliminated by the diurnal windingvup and down) then therewill still be the possi bility to take the mines up, clean and to laythem again, at least in mine-fields of defensive nature.

I claim as my invention:

A depth regulator for a submarine mine having mooring means therefor,including a mooring cable, said depth regulator comprising a rotatabledrum, a casing therefor, a rope coiled thereon and adapted to beconnected to said mooring cable, a rotatable axle carrying said drum,means intermediate said axle and said drum for transmitting rotation tosaid drum in either direction, a turbine operatively connected to saidaxle, and a safety-gear intermediate said rope and said mooring cable,comprising a. spring-controlled bolt movably mounted in said casing, ameans retaining said bolt in position, chain-links intermediate saidmooring cable and said rope and held by said bolt in inactive positionand adapted to operatively connect said mooring cable with said ropeupon the release of said bolt.

DEMETER RUDMANN.

